Definition of Biodiesel

Biodiesel is a liquid fuel from plants that can replace mineral diesel. According to the American Society for Testing and Materials biodiesel is "monoalkyl ester of long chain fatty acids derived from renewable resources such as vegetable oils or animal fats, for use in Diesel engines".

It is produced from renewable resources such as vegetable oils, soy, rapeseed / canola, sunflower, palm and others, as well as animal fats through a process called transesterification.

The transesterification consists basically of mixing the vegetable oil or fat with an alcohol (usually methanol) and an alkali (caustic soda). After a rest period, was decanted byproduct of biodiesel glycerol.

Increasingly refers to alkyl esters of vegetable oils or animal fats and oils or fats to themselves, used as fuel in Diesel engines.